- Update to 5.3.4
## Bug Fixes
### astropy.io.misc
* Updated ``astropy.io.misc.yaml`` so ``dump()` with a numpy
object array or ``load()`` with YAML representing a Numpy
object array both raise ``TypeError``. This prevents problems
like a segmentation fault. [#15373]
### astropy.io.votable
* Fixed a bug in ``convert_to_writable_filelike`` where
``GzipFile`` was not closed properly. [#15359]
### astropy.units
* In VOUnit, the spaces around the slash were removed in the
formatting of fractions, and fractional powers now also use the
"**" operator. [#15282]
* We now ensure that the unit ``u.cgs.cm`` is just an alias of
``u.si.cm``, instead of a redefinition. This ensures that
``u.Unit("cm") / u.cm`` will reliably cancel to dimensionless
(instead of some "cm / cm"). [#15368]
### astropy.utils
* For ``Masked``, ``np.ptp`` and the ``.ptp()`` method now
properly account for the mask, ensuring the result is identical
to subtracting the maximum and minimum (with the same
arguments). [#15380]
## Other Changes and Additions
* Compatibility with Python 3.12. [#14784]
* Replaced the URL of ``IETF_LEAP_SECOND_URL`` because the
original is now defunct and IETF now defers to IANA for such
look-up. [#15421]